Sensing control for a road building machine

ABSTRACT

A sensing device and system for controlling the horizontal and/or vertical position of a steerable, vertically adjustable road building machine. The device including a movable dial with exposed contacts about its periphery which make connection with fixed contacts upon movement thereof in response to relative movement of the machine horizontally or vertically to a preset line to operate electrically a power means to restore the machine to a desired position. The system affords the operation of a signal if any abnormal movement is sensed as may happen if the preset line ends or breaks and the electrical switching is bypassed which would normally perform a control function to adjust for the relative movement.

United States Patent Rink [541 SENSING CONTROL FOR A ROAD BUILDING MACHINE [72] Inventor: Richard H. Rink, Huron, S. Dak.

[73] Assignee: Huron Manufacturing Corporation, Hu-

ron, S. Dak.

[22] Filed: Aug. 26, 1970 [21] Appl. No.: 66,990

1 51 July 4, 1972 FOREIGN PATENTS OR APPLICATIONS 999,950 7/1965 Great Britain ..37/DIG. 20

Primary Examiner-John W. Caldwell Assistant ExaminerMichael Slobasky Attorney.lohn C. Barnes [57] ABSTRACT A sensing device and system for controlling the horizontal and/or vertical position of a steerable, vertically adjustable road building machine. The device including a movable dial with exposed contacts about its periphery which make connection with fixed contacts upon movement thereof in response to relative movement of the machine horizontally or vertically to a preset line to operate electrically a power means to restore the machine to a desired position. The system affords the operation of a signal if any abnormal movement is sensed as may happen if the preset line ends or breaks and the electrical switching is bypassed which would normally perform a control function to adjust for the relative movement.

5 Claims, 6 Drawing Figures SENSING CONTROL FOR A ROAD BUILDING MACHINE BACKGROUND OF THE INVENTION The present invention relates to an improved sensing device and an improved control system for road building machines and in one aspect to a device to steer and vertically position the machine relative to a preset line.

The prior art devices have included four-way hydraulic valve devices which were connected to direct fluid to or from a ram or to bypass the fluid in the normal position. The use of electrically controlled valves however reduces the amount of plumbing necessary to reposition the sensing devices since the conductors for the electrical devices are more easily positioned and moved than high pressure hydraulic fluid conduits or hoses.

The system of the present invention also provides a sensitive control to maintain accurate alignment of the road building machine with the sensitivity being adjustable to afiord the desired degree of accuracy.

The system of the present invention affords the capability of also having a signaling device to alert the operator of an unusual occurrence such as the machine suddenly moving out of line or off grade, the preset line breaking or the line stopping. This alarm actuator is built into the sensing device and operates the signaling device, e.g., a horn through the control panel.

SUMMARY OF THE INVENTION The sensing device comprises a housing for an angularly rotatable dial about which are electrical contacts which make or break circuits when contacted by fixed contacts biased against the periphery of the dial. The dial is rotated upon movement of an elongated arm which is attached to a rotatable shaft supporting the dial and formed to ride along the preset line. The arm is biased against the line and in the event of an abnormal movement the arm causes the dial to rotate against a stop closing a circuit to the alarm or signaling device. The control system permits a number of sensing devices to be joined to the control panel, such that each will operate a power means to adjust the machine position in some predetermined manner. The power means are preferably solenoid operated valves. These valves are gauged or stacked to be centrally located on the road building machine.

The advantages and improvements provided by the present invention will be described in greater detail below with references made to the accompanying drawing wherein:

DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a road building machine in operation and moving along a preset guide and grade line;

FIG. 2 is a side elevational view of a sensing device according to the present invention;

FIG. 3 is a rear elevational view of the device of FIG. 1 partly in section to show the interior parts;

FIG. 4 is an end view partially in section of the sensing device of FIGS. 2 and 3;

FIG. 5 is a plan view of the sensing device with the cover plate removed to show the interior members; and

FIG. 6 is a schematic wiring diagram.

Referring now to the drawing and particularly to FIG. 1, the road building machine generally designated 10 comprises a main frame 1 1 across which is formed a hopper for receiving premixed concrete. The frame 11 is supported at each corner by an arm 12 pivoted thereto at one end and carrying a spindle l4 and a pneumatic transport wheel 15 at its other end. Each spindle is adjustable about a vertical axis relative to the arm with opposed wheels being joined together such that the wheels on the forward end of the machine (the end toward the left as viewed in FIG. 1) move together and the wheels at the rear of the machine move together in response to the actuation of separate hydraulic rams (not shown). Each of the arms 12 are movable by operation of a hydraulic ram 16 to raise or lower the position of the frame 1 l to the predetermined grade line desired. The grade and position of the machine 10 are detemiined by a preset guide and grade line 17.

The road building machine illustrated is adapted for slip forming the concrete to form the road surface. The control of the hydraulic rams for steering the front and rear wheels and for independently controlling the rams 16 along the near side of the machine as shown in FIG. 1 and for controlling the rams 16 on the far side together utilizing five sensing devices generally designated 20. Each sensing device is substantially the same, and one of the devices is illustrated in detail in FIGS. 2, 3, 4, and 5.

Each sensing device 20 comprises a housing 21 adapted to be adjustably mounted on a rod fixed to the road building machine 10. The housing 21 has a generally rectangle box-like configuration comprising a pair of opposed side walls 22 and 23, end walls 24 and 25, a bottom plate 26, and a cover plate 27. A mounting bracket 28 is secured to the side wall 22 to mount the sensing device 20 on a rod supported from the road building machine 10. A rotatable shaft 30 is journaled in the opposed side walls 22 and 23 and has one end extending outwardly of the housing beyond the side wall 23.

The inner end of the shaft 30 supports between the side walls a dial 32 which is formed generally in the shape of a disk with concave peripheral portions and a hub 33 which extends along the shaft 30. The hub 33 has a set screw to fixedly mount the dial 32 to the shaft 30.

The dial 32 has a pair of parallel conductive members 34 and 37 extending from one peripheral edge along opposite sides of the shaft 30 to the opposite peripheral edge (see FIG. 3) to define on opposite sides of a diameter a pair of exposed electrical contact surfaces. The conductive member 34 defines a pair of exposed contacts 35 and the conductive member 37 defines a pair of exposed contacts 38.

A pair of fixed contacts 40 and 42 are supported from the end wall 24, one on each side of the diameter such that one fixed contact can engage the dial on the periphery on one side of a said diameter and the contacts 35 and 38 on that one side, and the other contact engages the other exposed contacts 35 and 38 on the opposite side of the diameter. The lower contact 40, as viewed in FIG. 3, is fixed on the end wall 24 and comprises a resilient conductive member which is urged toward the periphery of the dial 32.

The other fixed contact 42 comprises a resilient conductive member supported from a support 43 and having its free end biased into engagement with the periphery of the dial 32. The support 43 is mounted on two parallel pins 44 and 45 about which are springs 46 to urge the support toward the end wall 24. The support 43 is movable against the bias of the springs 46 by means of a set screw 48 which is threaded in the end wall 24 and engages the support 43. Adjustment of the set screw 48 moves the contact 42 relative to the exposed contact 38 adjacent which it engages the dial 32. This adjustment of the contact 42 relative to the exposed contacts increases the sensitivity of the sensing device such that there will only be a small angular displacement before the contact 42 or 40 engages one of the contacts 38.

On the extended end of the rotatable shaft 30 is supported a counterbalanced sensing arm 50 in the form of a rod bent to rest on or which is adapted to contact the side of the preset guide and/or grade line 17 and which will afford rotation of the dial upon relative movement of the road building machine frame 11 relative to a predetermined position with the preset line. The arm 50 is adjustably supported in a bracket 51 which bracket is fixed by a set screw 52 to the extended end of the shaft 30. An opening in the bracket 51 receives the arm 50 and a thumb screw 53 holds the arm in place. A weight 55 is supported on the rod forming the arm 50 and is secured in a predetermined adjusted position by means of a set screw.

When the machine is set as desired, the arm 50 is adjusted relative to the bracket 51 to engage the preset line. The counterweight 55 is then adjusted on the end of the arm opposite the end contacting the line such that the rod is at times urged by the weight 55 against the line or the weight of the arm urges it against the preset line and the weight 55 serves as a counterbalance to set the urging force at a desired level. The force is such that relative movement between the machine frame and the preset line will cause rotation of the shaft 30 and the dial 32. The force urging the sensing arm 50 into contact with the preset line is sufiicient such that should the machine move completely away from the line, the line break, or the line end, the arm would fall causing an extraordinary amount of rotation of the dial 32 such that one recessed portion of the dial contacts a stop member 58 on the end wall 25. This movement also registers an exposed contact 38 with a fixed contact to sound a signalling device such as a horn, flashing light or other signaling means, but one which is preferably audible to alert the driver above the other inherent noises associated with machines of this type.

As indicated in the schematic drawing, a control system for the road building machine is illustrated which includes five sensing devices 60-64, a control panel 65, five solenoidoperated valves 66-70 for use in a hydraulic circuit to operate the hydraulic rams l6 and the rams connected to the front and rear steering mechanisms, a signaling device in the form of a horn 71 and to a source 72 of voltage.

For purposes of description the reference numerals 34, 35, 37, 38, 40 and 42 will be used for the contacts etc. in each sensor 60-64 and will identify the same parts in F IG. 6 as in FIGS. 2-5. The terminals 73, 74, 75, and 76 connected to the members 34, 37, 40 and 42, respectively (F 165 2-5) are illustrated passing through a coupling or terminal 77 and suitable connections are shown schematically in FIG. 6.

The sensor 60 is used to steer the front of the machine through operation of the valve 69 and the fixed contacts 40 and 42 cause the valve to operate, via solenoids, to turn the front wheels toward and away from the line 17. The sensor 63 is used to guide the rear wheels by operation of valve 66 through fixed contacts 40 and 42 engaging a contact 38 on member 37.

The sensor 61 controls the elevation of the left front comer of the frame 11 via valve 68 and sensor 62 controls the left rear corner via valve 67. Sensor 64 is positioned on the right side of the frame intermediate its ends to control the elevation of said right side via its contacts 40 and 42 operating the solenoids on valve 70 to raise or lower the side respective under control of the rams 16 on said right side.

The sensors and valves are connected through suitable terminals or bus bars on the control panel 65. Also, all the conductive members 34 of each sensor 60-64 are connected through the panel to operate the horn 71. The born 71 is connected to the panel by suitable terminals and connectors. The system is energized by a suitable source of voltage 72 connected to the panel by a terminal and connected to each conductive member 37 to each sensor 60-64. Thus, angular rotation of the dials and thus the conductive members 34 and 37 due to relative movement between the machine frame and the preset line. cause the various solenoids on the valves to operate the valve in a manner to afiord readjustment of the machine frame to the predetermined desired position.

Having described the present invention with reference to the accompanying drawing it will be understood that various changes and modifications are contemplated without departing from the spirit and scope of the present invention as defined in the appended claims.

What is claimed is:

1. A sensing device adapted for electrically controlling the operation of power means for steering and vertically positioning a road building machine relative to a preset line, said device comprising a housing,

means for mounting said housing to the frame of a said road building machine,

a rotatable shaft journaled by said housing and having an inner and an outer end,

a dial positioned in said housing and supported for movement with the inner end of said shaft, said dial having a plurality of exposed contacts spaced about its periphery including at least two pairs of contacts on opposite sides of a diameter, with a contact on one side being electrically connected to an exposed contact on the other side,

a pair of fixed contacts supported by said housing and being positioned to engage the periphery of said dial and join with said exposed contacts upon rotational movement of said dial,

a counterbalanced sensing arm connected to said outer end of said shaft, said arm being adapted for contact with a said preset line and for rotating said dial upon relative movement of said road building machine frame and said preset line and afford contact between an exposed contact and a fixed contact to perform a control function, and

terminals to electrically connect said connected exposed contacts and said fixed contacts to a control panel.

2. A device as claimed in claim 1 wherein means are provided for adjusting the position of at least one of said fixed contacts along the periphery of dial for adjusting the sensitivity of said device to said relative movement.

3. A device as claimed in claim 1 wherein said counterbalanced sensing arm comprises an elongated rod,

means for adjustably connecting said rod to the outer end of said shaft,

a weight supported by said rod, and

means for adjusting the position of said weight along said rod to maintain said rod in contact with a said preset line.

4. A device as claimed in claim 1 further comprising a control panel, said control panel including bus bars adapted for connection to the four terminals of said device and a plurality of other devices and comprising a circuit adapted to connect a pair of said exposed contacts of each device to an alarm actuating device,

a circuit adapted to connect the other pair of said exposed contacts to the source of voltage, and

means for connecting the fixed contacts of each device to a separate terminal for operation of electrical control devices for the adjustment of a said road building machine.

5. A control system for operating hydraulic rams to adjust the position of a road building machine relative to a preset grade and guide line, said system comprising a plurality of solenoid operated hydraulic valves;

a plurality of sensing devices for producing electrical signals in response to relative movement of a said machine to said line from a predetermined position, each said sensing device comprising a housing,

means for mounting said housing to the frame of a said road building machine,

a rotatable shaft journaled by said housing and having an inner and an outer end,

a dial positioned in said housing and supported for movement with the inner end of said shaft, said dial having a plurality of exposed contacts spaced about its periphery including at least two pairs of contacts on opposite sides of a diameter with a contact on one side being electrically connected to an exposed contact on the other side,

a pair of fixed contacts supported by said housing and being positioned to engage the periphery of said dial and join with said exposed contacts upon rotational movement of said dial,

a counterbalanced sensing arm connected to said outer end of said shaft, said arm being adapted for contact with a said line and for rotating said dial upon relative movement of said road building machine frame and said line and afiord contact between an exposed contact and a fixed contact to perform a control function, and

a plurality of terminals connected one to each fixed contact, and one to each connected pair of exposed contacts; and

a control panel including circuit means adapted for contact to said plurality of sensing devices and to said plurality of said valves, said circuit means including means for supplying a source of voltage to one of said connected pair of exposed contacts, for connecting a signaling device to the other connected pair of exposed contacts and a plurality of terminals for connection of each fixed contact of each sensing device to a said valve for the operation thereof, whereby if a said road building machine moves horizontally away from said line a sensing device will sense the movement to operate a valve in response to rotation of a said shaft, if the machine moves vertically another sensor will sense the movement to operate a valve to return the machine to its preset condition and if said line ends or breaks said arms will cause an abnormal movement of said dial to close an electrical connection between a said sensing device and a said signaling device to alert the operator, and in so moving will not cause operation of any one of said valves but will continue on the same heading as before coming to end of line or breaking of string.

"I t t 

1. A sensing device adapted for electrically controlling the operation of power means for steering and vertically positioning a road building machine relative to a preset line, said device comprising a housing, means for mounting said housing to the frame of a said road building machine, a rotatable shaft journaled by said housing and having an inner and an outer end, a dial positioned in said housing and supported for movement with the inner end of said shaft, said dial having a plurality of exposed contacts spaced about its periphery including at least two pairs of contacts on opposite sides of a diameter, with a contact on one side being electrically connected to an exposed contact on the other side, a pair of fixed contacts supported by said housing and being positioned to engage the periphery of said dial and join with said exposed contacts upon rotational movement of said dial, a counterbalanced sensing arm connected to said outer end of said shaft, said arm being adapted for contact with a said preset line and for rotating said dial upon relative movement of said road building machine frame and said preset line and afford contact between an exposed contact and a fixed contact to perform a control function, and terminals to electrically connect said connected exposed contacts and said fixed contacts to a control panel.
 2. A device as claimed in claim 1 wherein means are provided for adjusting the position of at least one of said fixed contacts along the periphery of dial for adjusting the sensitivity of said device to said relative movement.
 3. A device as claimed in claim 1 wherein said counterbalanced sensing arm comprises an elongated rod, means for adjustably connecting said rod to the outer end of said shaft, a weight supported by said rod, and means for adjusting the position of said weight along said rod to maintain said rod in contact with a said preset line.
 4. A device as claimed in claim 1 further comprising a control panel, said control panel including bus bars adapted for connection to the four terminals of said device and a plurality of other devices and comprising a circuit adapted to connect a pair of said exposed contacts of each device to an alarm actuating device, a circuit adapted to connect the other pair of said exposed contacts to the source of voltage, and means for connecting the fixed contacts of each device to a separate terminal for operation of electrical control devices for the adjustment of a said road building machine.
 5. A control system for operating hydraulic rams to adjust the position of a road building machine relative to a preset grade and guide line, said system comprising a plurality of solenoid operated hydraulic valves; a plurality of sensing devices for producing electrical signals in response to relative movement of a said machine to said line from a predetermined position, each said sensing device comprising a housing, means for mounting said housing to the frame of a said road building machine, a rotatable shaft journaled by said housing and having an inner and an outer end, a dial positioned in said housing and supported for movement with the inner end of said shaft, said dial having a plurality of exposed contacts spaced about its periphery including at least two pairs of contacts on opposite sides of a diameter with a contact on one side being electrically connected to an exposed contact on the other side, a pair of fixed contacts supported by said housing and being positioned to engage the periphery of said dial and join with said exposed contacts upon rotational movement of said dial, a counterbalanced sensing arm connected to said outer end of said shaft, said arm being adapted for contact with a said line and for rotating said dial upon relative movement of said road building machine frame and said line and afford contact between an exposed contact and a fixed contact to perform a control function, and a plurality of terminals connected one to each fixed contact, and one to each connected pair of exposed contacts; and a control panel including circuit means adapted for contact to said plurality of sensing devices and to said plurality of said valves, said circuit means including means for supplying a source of voltage to one of said connected pair of exposed contacts, for connecting a signaling device to the other connected pair of exposed contacts and a plurality of terminals for connection of each fixed contact of each sensing device to a said valve for the operation thereof, whereby if a said road building machine moves horizontally away from said line a sensing device will sense the movement to operate a valve in response to rotation of a said shaft, if the machine moves vertically another sensor will sense the movement to operate a valve to return the machine to its preset condition and if said line ends or breaks said arms will cause an abnormal movement of said dial to close an electrical connection between a said sensing device and a said signaling device to alert the operator, and in so moving will not cause operation of any one of said valves but will continue on the same heading as before coming to end of line or breaking of string. 